Organometallics 1988, 7, 1318-1323
1318
Tetranuclear Homo- or Heteroblmetallic Asymmetric Palladium( I 1)-Platinum( I I)Complexes with Single Halide Bridaes. Molecular Structure of
R. Usdn,” J. ForniBs, M. Tomds, and B. Menjdn Departamento de 06mica Inorghica, Instituto de Ciencia d? Materlaies de Aragh, Universidad de Zaragoza-Consejo Superior de Investigaciones Cientificas, 50009 Zaragoza, Spain
A. J. Welch Department of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, Great Britain Received October 1, 1987
Treatment of c~~-[M(C&,)~(THF),] (M = Pd, Pt; X = F, C1; THF = tetrahydrofuran) with M’X‘,(COD) (M’ = Pd, Pt; X’ = C1, Br, I; COD = 1,5-cyclooctadiene)results in the formation of homo- and heteronuclear which are binuclear (n palladium or platinum complexes of general formula [ (C,X,),M(p-X’),M’(COD)]. , = 1) in CHCl:, solutions. The molecular structure of [Pt(C6F,),(p-Br)Pd(coD)(p-Br)Pt(C6F5)2(p-Br)Pd(C0D)(p-Br)] has been established by single-crystal X-ray crystallography, showing that the complex is tetranuclear in the solid state. The molecule resides on a center of symmetry and can be regarded as an eight-membered ring skeleton being made up of two “Pt(C6F5)2n and two “Pd(~4-1,5-C8H,z)” groups in an alternate way connected b single bromide bridges. Crystal data: monoclinic, a = 26.742 (6) A, b = 9.3916 (18) A, c = 18.133 (5) = 108.424 (22)”; space group C2/c; 2 = 4. The structure has been solved from diffractometer data by direct and Fourier methods and refined by full-matrix least squares to R = 0.0369 for 3059 observed reflections.
g;
Introduction Homobinuclear Pd(I1) or Pt(I1) complexes with halide bridges most frequently contain the moiety (X = halogen).
When two of the four terminal ligands are neutral (L = CO, olefin, group VB ligands) and the other two are anionic (X’ = halide, alkyl, aryl), neutral complexes of the type [M,(p-X),L,X’,] result. If the four terminal ligands are anionic (X’ = halide, aryl), anionic complexes [M,(pX)2X’4]2-are ~ b t a i n e d . l - ~ For binuclear complexes of the type [M,(p-X),X’,L,] three isomers, A, B, and C, are theoretically expected, but
A
trans
B
cis
C gem or asymm
most of the hitherto reported complexes adopt structure A and complexes with structure B have been described only oc~asionally.~,~ No complex with geometry C has (1)Wells, A. F. Structural Inorganic Chemistry, 5th ed.; Oxford University Prese: Oxford, 1984;p 1232 and references given therein. (2) Maitlis, P. M.; Eepinet, P.; Russell, M. J. H. Comprehensive Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Abel, E., Eds.; Pergamon: New York, 1982;p 3% and references given therein. (3)Usbn, R.; FomiCs, J.; Martinez, F.; Tomb, M. J. Chem. Soc., Dalton Trans. 1980,888. (4)U s b , R.; FomiBs, J.; Martinez, F.; Tomb, M.; Reoyo, I. Organometallics 1983,2, 1386. (5)Puddephatt, R. J.; Thompson, P. J. J.Chem. Soc., Dalton Trans. 1977,1219. (6)Anderson, G.K.;Cross, R. J.; Rycroft, D. S. J.Chem. Res., Synop. 1977,120;J. Chem. Res. Miniprint 1601.
previously been reported, despite intensive research on binuclear palladium and platinum derivatives during the last ca. 50 years. Moreover, the only heterobimetallic halide-bridged PdPt complexes isolated and unambiguously characterized so far are of type [(PR,)ClPd(p-Cl),PtCI(PR,)] (structure A),7 although other complexes containing bidentate“l8 or polydentatelg bridging ligands have been described. To the best of our knowledge, the only homo- or heterobinuclear Pd(I1)-Pt(I1) complexes with both metal atoms linked by a single halide bridge are of the type [ (N-C-N)M’(p-X)M(N-C-N)]+ (where (N-C-N) = o,o’(Me2NCHz)2C6H3; M, M’ = P d or Pt; X = halide).20~21 (7)Clark, H. C.; Ferguson, G.; Jain, V. K.; Parvez, M. Inorg. Chem. 1985,24,1477. (8)Pringle, P. G.;Shaw, B. L. J.Chem. Soc., Dalton Trans. 1983,889. (9)Langrick, G. R.; McEwan, D. M.; Pringle, P. G.; Shaw, B. L. J. Chem. Soc., Dalton Trans. 1983,2487. (10)Blagg,A.;Hutton, A. T.; Pringle, P. G.; Shaw, B. L. J.Chem. Soc., Dalton Trans. 1984,1815. (11)Langrick, C.R.; Pringle, P. G.; Shaw, B. L. J. Chem. Soc., Dalton Trans. 1984,1233. (12)Cooper, G.R.; Hutton, A. T.; Langrick, C. R.; McEwan, D. M.; Pringle, P. G.; Shaw, B. L. J. Chem. Soc., Dalton Trans. 1984, 855. (13)Hassan, F. J. M.; Marklam, D. P.; Pringle, P. G.; Shaw, B. L. J. Chem. Soc., Dalton Trans. 1985,279. (14)Hutton, A.T.;Pringle, P. G.; Shaw, B. L. J. Chem. SOC.,Dalton T r a m . 1985,1677. (15)Hutton, A. T.; Langrick, G. R.; McEwan, D. M.; Pringle, P. G.; Shaw, B. L. J. Chem. Soc., Dalton Trans. 1985,2121. (16)Can, S.W.; Shaw, B. L.; Thomton-Pett, M. J. Chem. Soc., Dalton Trans. 1985,2134. (17)Deese, W. C.;J o b o n , D. A. J. Organomet. Chem. 1982,232,325. (18)ForniCs, J.; Martinez, F.; Navarro, R.; Redondo, A.; Tomb, M.; Welch, A. J. J. Organomet. Chem. 1986,316, 351. (19)Usbn, R.; Gimeno, J.: ForniCs, J.; Martinez, F.; Fernhdez, C. Inorg. Chim. Acta 1982,63,91. (20)Grove, D.M.; van Koten, G.; Ubbels, H. J. C., Spek, A. L. J. Am. Chem. Soc. 1982,104,4285.
0276-7333/88/2307-1318$01.50/0 0 1988 American Chemical Societv
Organometallics, Vol. 7, No. 6, 1988 1319
Asymmetric Palladium(Il)-Platinum(Il)Complexes
Table I. Analytical Results (Calculated Values in Parentheses) and Other Characteristic Data C H X mp,
[(C,F,),Pt(p-C1),Pt(COD)In (1) [(C,F,),Pt(r-Br),Pt(cOD)ln (2) [(C,F,),Pt(r-I)zPt(COD)In(3) [ (C,C~,)ZP~(~~-I)ZP~(COD)I~ (4) [(C,F,)zPd(r-C1),Pd(coD)ln( 5 ) [(C~s)~Pd(cc-Br)zPd(COD)ln (6) [(C,Cl,),Pd(r-Cl),Pd(COD)In (7) [ (C~Fs),PtG-CI)zPd(COD)In (8) [ (C,F,),Pt(r-Br),Pd(COD)l.(9) [(C,cl,)~Pt(cc-Br),Pd(coD)ln (10) [(Cg,)zPd(r-Br)zPt(C0D)ln (11) [ (CsCl6)zPd(rL-Br)zPt(COD) In (12) a
26.7 (26.6) 24.2 (24.2) 22.1 (22.1) 18.90 (19.20) 33.15 (33.10) 29.80 (29.50) 26.85 (26.95) 29.55 (29.50) 26.90 (26.60) 22.25 (22.50) 26.40 (26.60) 22.65 (22.50)
1.3 (1.35) 1.4 (1.2) 1.15 (1.10) 0.95 (0.95) 1.85 (1.65) 1.75 (1.50) 1.35 (1.35) 1.95 (1.50) 1.50 (1.30) 1.15 (1.10) 1.45 (1.20) 1.10 (1.10)
7.6 (7.8) 15.9 (16.1)
842 (903) 999 (992) 1025 (1086) a a 776 (815) a 762 (815) 877 (903) a 918 (904) a
9.20 (9.75) 19.10 (19.60) 47.75 (47.75) 8.55 (8.70) 17.90 (17.70) 17.55 (17.70)
O C
189 dec 169 dec 170 dec 215 dec 130 dec 142 dec 160 dec 170 dec 150 dec 165 dec 107 dec 191 dec
Not soluble enough in CHCl:, for molecular weight determination.
Table 11. Some Relevant IR Absorptions (in cm-l) CnXs
X[PdClZ(COD)] [PdBrz(COD)] [PtClZ(COD)I
COD 1524, 1512, 1423 684 560,454 1524, 1514, 1420 697 553,450 1496, 1430 695 580, 474, 455 693 574,469, 1500, .... 1425 448 690 566,459, 1500, 1422 443 695 575,469 .... 1430 (sh) 695 572, 466, .... 1430 (sh) 450 .... 1428 690 566, 459 1504, 1430 694 560, 458 1518, 1427 682 550, 447 1515, 1425 680 545, 440 1520, 1502, 1424 ... 555, 452 1520, .... 1430 679 556,452 1524, .... 1425 671 544, 436 1520, 1503, 1423 549,444 ........ 1430 (ah) 685 564, 464 1500, 1432 ... 567, 464
sensitive
u(M-C)
...
....
... ... ...
... ...
... ... ...
... ...
... ...
215
....
... ...
1505,961 1503,960
350,340, 312 215
.... .... ....
...
....
Here, we report the synthesis of homo- or heteronuclear Pd(I1)-Pt(I1) complexes of the type [ (C6X5)2M-(pX’),M+’(COD)], which are binuclear (n = 1)in chloroform solution and, according to their NMR spectra, seem to be the first asymmetric (structure C) binuclear Pd-Pt complexes. In the solid state, however, they rearrange to give a tetranuclear eight-membered ring with alternating Pd and Pt atoms singly bridged by halide ions, [M(C,X,),(p-X’)M’(COD)(p-X’)M(C,X,),(p-X’)M’(COD)(p-X’)], as has been established by an X-ray crystallographic study on [ (C,F,)zPt(p-Br)Pd(COD)]p Preliminary results on these complexes have been reported earlier?, and very recently other authorsz3 have claimed the synthesis of mixed binuclear asymmetric complexes with double halide bridges but without structural support.
Results and Discussion We have recently reported the synthesis of cis-[M(C,X,),(THF),] (M = Pd, Pt; X = F, C1; T H F = tetrahydrofuran) and have shown that they are excellent precursors for the preparation of ~ i s - d i c a r b o n y lor~ ~cis~~~ (21) Terheijden, J.; van Koten, G.; Grove, D.M.; Vrieze, K.; Spek, A. L. J. Chem. Soc., Dalton Trans. 1987, 1359. (22) Usbn, R. Pure Appl. Chem. 1986,58,647. (23) L6pez, G.; Garcia, G.; Haro, C.; Shchez, G.; Garda, J. J. Organomet. Chem. 1986,317, C23. (24) U s h , R.; ForniBs, J.; T o m b , M.; Menjbn, B. Organometallics 198S, 4, 1912. (25) Usbn, R.; Fornigs, J.; T o m b , M.; Menjbn, B. Organometallics 1986, 5, 1581.
817, 806 814, 803 807, 798 847, 851 800, 791 796, 783 840, 834 814, 803 812, 802 849,841 803, 796 842,838
others
... ...
u(M-X) 336-327, 298
...
337, 316
...
... 1502, 963-927 630, 620 1328, 1310, 1290, 1213,676 ... 1500, 960 327, 312, 285, 270 ... 1500, 957 ... 624,615 1327, 1317, 1290, 1220, 675 330, 282, 255 ... 1500, 960 335, 325, 305, 300 ... 1500,958 ... 832, 622 1331, 1320, 1292, 1214, 678 ... 1503,960 ... 623, 613 1324, 1317, 1288, 1220,674 ...
...
...
bis(acetylene)2e complexes of palladium and platinum because of the facile displacement of the neutral T H F ligands from the original complexes. Reaction of c~-[M(C,X,),(THF)~] with complexes of the type cis-M’X’,Lz (M’ = Pd, Pt; X’ = halide; L = neutral ligand) is a promising approach for the synthesis of binuclear asymmetric homo- or heterometallic complexes, as represented in eq 1. C/.S-CM(C~X,),(THF)~I
+
-
c/.s-CM’X’~L~I
To ensure that the complexes MX’,L, have the required cis configuration, we have used palladium(I1) or platinum(I1) complexes containing a chelating ligand (L2 = COD = l,bcyclooctadiene). The room-temperature (1:l) reaction of c~~-[M(C,X,)~(THF),] and cis-[M’X’,(COD)] causes in most cases a visible color change. The pentachlorophenyl derivatives (X = C1) precipitate out during the reaction, while the isolation of the pentafluorophenyl complexes (X = F) requires evaporation of the solvent (CH,Cl,). Appropriate choice of the reagents allows the synthesis of homo- or heteronuclear complexes (eq 2). ~~
(26) Usbn, R.; ForniBs, J.; T o m b , M.; Menjbn, B.; Welch, A. J. J. Organomet. Chem. 1986, 304, C24.
1320 Organometallics, Vol. 7, No. 6, 1988 ncis-M(C6X5),(THF), + nM’X’,(COD)
-
[(C6X5),M(cl-X’),M’(c0D)]~ + 2nTHF (2) 1-12
M = M’ = Pt; X = F, X’ = C1 (l), Br (2),I (3); x = c1, X’ = I (4) M = M’ = Pd; X = F, X’ = C1 (5), Br (6); x = c1, X’ = c1 (7)
Usdn et al. Table 111. lgF NMR SDectrau rp
[(C,F,),Pt(r-Cl),Pt(COD)I, (1) [(C6F,),Pt(r-Br),Pt(COD)I, (2)
[(C,F,),Pt(r-I)zPt(COD)1, (3) [(C,F,),Pt(r-Cl),Pd(COD)]” ( 8 ) [(C,F5)2Pt(r-Br)2Pd(COD)]”(9) 6 referenced to CFCI,;
-120.1 -121.1 -120.0 -121.7 -120.9
-160.9 -162.5 -162.9 -162.7 -162.8
r’m
-164.1 -165.5 -165.5 -165.6 -165.6
“JPt-F,
494 390 485 507 504
J in Hz;solvent CDC13.
M = Pt, M’ = Pd; X = F, X’ = C1 (8), Br (9); X = C1, X’ = Br (10) M = Pd, M’ = Pt; X = F, X’ = Br (11); X =C1, X’ = Br (12) Table I collects analytical and other data for complexes 1-12. Table I1 lists some relevant IR absorptions: along with bands due to the neutral ligand (COD)27928 all the complexes show two bands assignable to the X-sensitive mode of the c&5 g r o ~ p which s ~ ~also ~ ~retain ~ ~ their cis positions. This is further supported by the observation of two absorptions due to v(M-C) in the pentachlorophenyl derivative^.^^ A maximum of four absorptions in the v(meta1-halide) region are also found (Table 11). The lgFNMR spectra of bis(pentafluoropheny1)platinum complexes 1,2,3,8,and 9 (the palladium complexes show decomposition during the time required to record the spectra) show three signals corresponding to F,, F,, and Fp,the first with platinum satellites (see Table 111). Both C y 5groups are equivalent and freely rotating around the Pt-C bonds. All the data 80 far discussed are compatible with a value of 1for n (eq 2), i.e. with a binuclear asymmetric structure for the reported complexes. Moreover, molecular weight determinations (isopiestic, in CHC1, solution) are in agreement with this view (Table I) for all the complexes which are soluble enough to permit the measurement 1, 2, 3, 6,8,and 9. All the complexes are soluble in acetone, and these solutions are nonconducting, and colorless or only pale yellow, in contrast with the deeply coloured solids. If acetone solutions of complexes 2 or 3 are vacuum evaporated to dryness, yellow solids are obtained. Their IR spectra show a strong absorption a t 1650 cm-’, which indicates the presence of coordinated acetone. By heating the yellow solids a t 60 OC under vacuum the original complexes 2 or 3 are recovered. Seemingly, an excess of acetone causes decomposition of the complexes (eq 3).
Figure 1. The molecular geometry of [Pt(C6F,),(~-Br)Pd(s41,5-C8H12)(r-Br)Pt(C6FS)2(~-Br)Pd(s4-1,5-CsH12)(~-Br)] complex (9).
-
e +OCMe
1/n[ (C,X,)zM(cl-X’)zM’(COD) 1, cis-[M(C6X5),(OCMe,),] + [M’X’,(COD)] (3)
4
Figure 2. Central core of complex 9.
(9) has been solved by single-crystal X-ray crystallography. Upon vacuum concentration of an acetone solution of General crystallographic information is presented in Table complex 3 yellow crystals of PtI,(COD) separate, in supV. Positional parameters and bond distances and angles port of the proposed decomposition scheme (eq 3). are given in Table VI and VII, respectively. The molecular Generally, solutions of the complexes in nondonor solstructure (Figure 1) shows a tetranuclear complex vents (CH2C12,CHC1,) show changes in color, some of [ (C,F,),Pt(cl-Br),Pd(COD)], with an eight-membered ring which are quite dramatic (see Table IV) which may be as central core formed by two palladium, two platinum, indicative of some structural change. To ascertain this and four bromine atoms. The ring has distorted chair possibility the structure of [ (CGF5)ZPt-(~-Br)zPd+(COD)] structure about a center of symmetry (Figure 2), and platinum atoms are linked to palladium through single bridging bromine atoms. The Pd-SPt, Pt-Pt, or Pd-ePd (27) Powell, D. B.; Leedham, T. J. Spectrochim. Acta, Part A 1972, distances are longer than 3.6 A, thus precluding any kind 28A, 337. (28) Maslowsky, E., Jr. Vibrational Spectra of Organometallic Comof M-M interaction. The environment around the platipounds; Wiley: New York 1977; p 455. num atom is almost square-planar; the angles between cis (29) Reference 28, p 437. ligand-metal bonds are in the range 87.2-95.0’. The Pt(30) Casabb, J.; Coronas, J. M.; Sales, J. Znorg. Chim. Acta 1974,11, 5. C1 and Pt-C7 distances are 1.975 (9) and 1.967 (9) 8,
Organometallics, Vol. 7,No. 6, 1988 1321
Asymmetric Palladium(II)-Platinum(I0Complexes
Table IV. ExDerimental Conditions in the Synthesis of Complexes 1-12 by Ea 2” and Other Data com p 1ex 1 2 3
4 5 6
7 8 9 10 11 12
cis-[M(c~X,)z(THF)zl, g (“01) 0.17 (0.25) 0.17 (0.25) 0.17 (0.25) 0.14 (0.17) 0.14 (0.28) 0.12 (0.21) 0.16 (0.22) 0.17 (0.25) 0.17 (0.25) 0.14 (0.17) 0.12 (0.21) 0.14 (0.19)
[M’X’z(COD)I, g b“) 0.093 (0.25) 0.137 (0.24) 0.071 (0.25) 0.094 (0.17) 0.070 (0.25) 0.079 (0.21) 0.063 (0.22) 0.071 (0.25) 0.090 (0.24) 0.063 (0.17) 0.097 (0.21) 0.087 (0.19)
yield, % 96 61 81 96 87 83 77 81 83 83 84 60
color solid yellow yellow yellow orange yellow orange red salmon garnet garnet brown yellow
CHzClzsoln yellow yellow orange orangeb orange red red green green greenb yellow orange
acetone soln colorless colorless yellow yellow yellow yellow yellow yellow yellow yellow colorless co1or1ess
“The reactions have been carried out in 20 mL of CH2Cl2;room temperature. For complexes 7 and 11 a t 0 “C. bScarcely soluble.
Table V. Crvstal Data for 9 formula mol w t source of crystals cryst size, mm cryst system space group a,
A
b, A
c.
A
%t
deg
v,A3
diffractometer
T. K radiatn A,
A
N(MOKa),cm-’ 0 range, deg mode data measd data reductn procedure data used (F 1 6 d F ) ) soln refinement model
C40H24Pd2Pt2Br4F20
1807.02 ~ - . solvent diffusion (CHZCl2;n-hexane), -30 OC 0.4 X 0.25 X 0.25 monoclinic c2/c 26.742 (6) 9.3916 (18) 18.133 (5) 108.424 (22) 4320.68 Enraf-Nonius CAD 4 185 f 1 Mo K a 0.71069 106.87; empirical absorption correction was applied@ 1-25; +h,+k,h:l W-28 scans 3788 CADABS;41no detectable crystal movement or decay over -63 X-ray hours 3059
direct methods (SHELX76), A F syntheses full-matrix least squares all atoms except hydrogen have been refined with anisotropic thermal parameters; the hydrogen atoms of the 1,5-cyclooctadiene rines has been daced in calculated posytions; groui Ys for hydrogen atoms (0.053 (11)A’) weighting scheme w-l = [u2(F) 0.0016P1 R 0.037 Rw 0.041 variables 308 largest shiftlesd, 0.01 final cycle largest peak, e/A3 1.13
+
similar to those observed in other complexes containing the “cis-Pt(C6F5)2”moiety.26~31*32 Palladium atoms are in an almost square-planar environment defined by the two bromines and by the midpoints of the olefinic carboncarbon bonds. The angle Br(1)-Pd-Br(2) is 86.61 (4)O, and the olefin midpoint-Pd-olefin midpoint angle is 86.4 (4)O. The C=C distances are C(13)-C(14) = 1.372 (14) A and C(l7)-C(l8) = 1.360 (15) A. The Pd-C(13), Pd-C(14), Pd-C(17), and Pd-C(l8) distances are 2.215 (91, 2.202 (lo), 2.222 (lo), and 2.193 (9) A, respectively, and the palladium-olefi midpoint distances are 2.099 and 2.100 A. Thus (31) Usbn, R.; Fornigs, J.; Tom& M.; Casas, J. M.; Cotton, F. A.; Falvello, L. R. J. Am. Chem. SOC.1985, 107, 2556. (32) UsBn, R.; ForniBs, J.; Menjbn, B.; Cotton, F. A.; Falvello, L. R.; Tomb, M. Inorg. Chem. 1985, 24, 4651.
Table VI. Fractional Atomic Coordinates (X104) and Equivalent Isotropic Thermal Parameters of Refined Atoms in Complex 9 X 2 B, A2 Y 1.24 (2) Pt 3418 (1) 8537 (1) 6582 (1) Pd Br 1 Br2 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10
c1 c2 c3 c4
c5
C6 c7 C8 c9 c10 c11 c12 C13 C14 C15
C16 C17 C18 c19 c20
2021 (1) 2807 (1) 2951 (1) 4590 (2) 5213 (2) 4847 (3) 3837 (3) 3217 (2) 4344 (2) 4941 (2) 4751 (3) 3956 (3) 3345 (2) 3880 (4) 4397 (4) 4710 (4) 4531 (4) 4025 (5) 3719 (4) 3817 (3) 4225 ( 4 ) 4540 (4) 4445 (4) 4043 (4) 3737 (4) 2095 (4) 1818 (4) 1219 (4) 923 (4) 1197 (4) 1531 (4) 1714 (5) 1862 (4)
7719 (1) 6541 (1) 9085 (1) 8751 (6) 11006 (7) 13635 (7) 14051 (6) 11840 (6) 6430 (6) 6266 (6) 8009 (9) 9900 (9) 10108 (6) 10179 (10) 10063 (10) 11197 (11) 12546 (11) 12738 (10) 11570 (10) 8284 (9) 7328 (9) 7206 (10) 8106 (12) 9038 (11) 9113 (10) 9583 (11) 8537 (11) 8466 (13) 8877 (15) 8375 (11) 9232 (11) 10711 (11) 10875 (11)
5782 (1) 6663 (1) 5184 (1) 6541 (4) 6557 (4) 6584 (4) 6611 (4) 6584 (3) 7440 (3) 8943 (4) 10003 (3) 9580 (4) 8090 (3) 6582 (5) 6563 (5) 6569 (6) 6587 (6) 6599 (6) 6592 (5) 7689 (5) 7953 (5) 8725 (6) 9267 (6) 9037 (6) 8275 (5) 6558 (5) 6789 (6) 6570 (6) 5717 (7) 5166 (6) 4939 (5) 5232 (7) 6091 (6)
1.36 (4) 2.07 (5) 2.34 (5) 2.87 (35) 3.30 (37) 4.19 (45) 3.55 (39) 2.50 (32) 2.68 (33) 2.81 (34) 4.22 (40) 5.15 (47) 2.67 (32) 1.65 (46) 1.86 (47) 2.14 (52) 2.60 (58) 2.70 (59) 1.96 (50) 1.30 (43) 1.60 (46) 2.11 (51) 2.25 (53) 2.40 (56) 1.73 (48) 1.91 (49) 2.41 (56) 2.94 (63) 3.67 (69) 2.33 (54) 2.15 (51) 3.21 (69) 2.56 (57)
the ‘‘Pd(C0D)” fragment in 9 has similar distances and angles to those observed in PdC12(1,5-COD).33 Dimensions involving the bridging bromide ligands are of interest: Pt-Br(1) and Pd-Br(1) are 2.524 (1)and 2.463 (1)A, respectively, whereas Pt-Br(2) and Pd’-Br(2) are 2.500 (1)and 2.455 (2) A, respectively. These M-Br distances are similar to those observed in other palladium34 and platinum35 complexes with bridging bromide. However, although the covalent radii of (square-planar) Pd(I1) and Pt(I1) are nominally the same (1.31 A),36the Pt-Br (33) Rettig, M. F.; Wing, R. M.; Wiger, G. R. J.Am. Chem. SOC.1981, 2980. (34) Sales, D. L.; Stokes, J.; Woodward, P. J.Chem. SOC.A 1968,1852. (35) Russell, D. R.; Tucker, P. A.; Whittaker, C. Acta Crystallogr., Sect. B Struct. Crystallogr. Cryst. Chem. 1975, B31, 2530. (36) Hartley, F. R. The Chemistry of Platinum and Palladium; Applied Science; London, 1973; p 8.
1322 Organometallics, Vol. 7, No. 6, 1988
UsBn et al.
Table VII. Bond Distances Brl-Pt Bra-Pt C1-Pt C7-Pt Brl-Pd Br2’-Pda C13-Pd C14-Pd C17-Pd C18-Pd C2-F1 C3-F2 C4-F3 C5-F4 Bra-Pt-Brl C 1-Pt-Br 1 C1-Pt-Br2 C7-Pt-Brl C7-Pt-Br2 C7-Pt-C 1 Brl-Pd-Br2’ C13-Pd-Brl C14-Pd-Brl C14-Pd-Cl3 C17-Pd-Br 1 C17-Pd-Cl3 C17-Pd-Cl4 C18-Pd-Brl C 18-Pd-C 13 C18-Pd-Cl4 C18-Pd-Cl7 Pd-Brl-Pt Pt-Br2-Pd’ c2-c1-Pt C6-C1-Pt C6-Cl-C2 C1-C2-F1 C3-C2-F1 c3-c2-c1 C2-C3-F2 C4-C3-F2 c4-c3-c2 C3-C4-F3 C5-C4-F3 c5-c4-c3 C4-C5-F4 C6-C5-F4 C6-C5-C4 a
2.524 (1) 2.500 (1) 1.974 (9) 1.967 (9) 2.463 (1) 2.455 (1) 2.215 (9) 2.201 (10) 2.221 (10) 2.193 (9) 1.341 (11) 1.364 (12) 1.327 (11) 1.334 (12) 95.0 (1) 175.4 (3) 87.2 (3) 90.1 (2) 174.6 (3) 87.6 (4) 86.6 (1) 93.3 (2) 90.2 (3) 36.2 (4) 163.4 (3) 88.5 (4) 81.6 (4) 160.5 (3) 81.0 (4) 95.8 (4) 35.9 (4) 93.7 (1) 117.6 (1) 124.2 (7) 122.9 (7) 112.9 (8) 117.8 (8) 118.6 (8) 123.6 (9) 120.5 (9) 118.7 (9) i20.8 (9) 119.3 (lo) 122.0 (10) 118.7 (9) 120.0 (10) 121.0 (11) 119.0 (10)
(A) and Bond Angles (deg) for Complex 9
Bon.d Distances C6-F5 1.361 (12) C8-F6 1.366 (10) C9-F7 1.348 (11) 1.331 (11) C10-F8 Cll-F9 1.350 (12) C12-Fl0 1.366 (10) c2-c1 1.399 (13) 1.377 (13) C6-Cl 1.354 (13) C3-C2 1.358 (14) c4-c3 1.373 (16) c5-c4 1.366 (14) C6-C5 1.377 (13) C8-C7 Bond Angles C l-C6-F5 119.2 (8) C5-C6-F5 115.9 (9) C5-C6-C1 124.9 (9) C8-C7-Pt 123.2 (7) C12-C7-Pt 123.3 (7) C12-C7-C8 113.3 (8) C7-C8-F6 119.7 (8) C9-C8-F6 115.8 (8) C9-C8-C7 124.5 (8) 121.5 (9) C8-C9-F7 C10-C9-F7 120.1 (9) C10-C9-C8 118.4 (9) C9-C 10-F8 118.6 (9) Cll-ClGF8 122.3 (9) c11-c1o-c9 119.1 (9) ClO-Cll-FS 117.9 (9) C12-C 11-F9 121.4 (9) c12-c11-c10 120.7 (9) C7-C 12-F 10 119.2 (8) Cll-ClZ-FlO 116.8 (8) Cll-C12-C7 123.9 (9) H13-Cl3-Pd 88.5 (2) C 14-C 13-Pd 71.4 (6) C 14-Cl3-Hl3 117.1 (6) C20-Cl3-Pd 110.1 (6) C20-Cl3-Hl3 117.1 (6) C20-Cl3-Cl4 125.8 (9) C 13-Cl4-Pd 72.4 (6) H14-Cl4-Pd 91.2 (3) H14-C 14-C 13 117.5 (6)
C12-C7 C9-C8 c10-c9 c11-c10 C12-cll C 14-C 13 C2M13 C15-Cl4 C16-Cl5 C17-Cl6 C18-Cl7 C19-Cl8 C20-Cl9
1.387 (13) 1.391 (13) 1.380 (14) 1.346 (15) 1.366 (14) 1.373 (14) 1.497 (14) 1.523 (15) 1.547 (15) 1.488 (16) 1.359 (15) 1.512 (14) 1.490 (15)
C15-C 14-Pd C15-Cl4-Cl3 C 15-C 14-Hl4 H15-C 15-C14 H 15’-C 15-C 14 C16-Cl5-Cl4 C1 6 415-H 15 C16-Cl5-Hl5’ H16-C16-C 15 H16’-C16-C15 C17-C16-C 15 C 17-Cl6-Hl6 C 17-Cl6-Hl6’ C16-Cl7-Pd H17-Cl7-Pd H17-Cl7-Cl6 C18-Cl7-Pd C 18-C 17-C 16 C 1 8 417-H 17 C17-C 18-Pd H18-Cl8-Pd H18-Cl8-Cl7 C 19-C l&Pd C 19-C 18-C17 C 19-C 18-H18 H19-Cl9-Cl8 H19’-C19-C18 C20-C 1 9 4 x 8 C20-Cl9-Hl9 C20-Cl9-Hl9’ c19-c20-c13 H20-C2O-C13 H20-C20-C19 H20’-C 20-C 13 H20’-C20-C 19
106.4 (7) 125.1 (10) 117.4 (6) 108.2 (6) 108.2 (6) 114.4 (9) 108.2 (7) 108.2 (7) 108.7 (7) 108.6 (6) 112.8 (9) 108.6 (7) 108.6 (6) 111.8 (7) 87.4 (3) 119.2 (7) 70.9 (6) 121.7 (10) 119.2 (6) 73.2 (6) 89.6 (3) 116.3 (6) 107.1 (7) 127.5 (9) 116.3 (6) 108.2 (6) 108.3 (6) 114.3 (9) 108.3 (6) 108.3 (6) 115.7 (9) 107.9 (5) 107.9 (6) 107.9 (5) 107.9 (6)
By symmetry.
bonds are both longer than Pd-Br, reflecting the different trans influences of the C6F5and olefin ligands. The two bromide bridges in 9 are themselves quite different in that the Pt-Br-Pd angle at Br(1) is 93.64 (4)’ while that at Br(2) is much wider, 117.62 ( 4 ) O . Moreover, the Br(1)-Pt and Br(1)-Pd bonds are both longer, by 0.024 and 0.008 A, respectively, than the corresponding bonds from Br(2). The tetranuclear single-bridgedstructure of complex 9 in the solid atate contrasts with the usual binuclear double-bridged structures of halide bridged palladium or platinum complexes (eq 1) and is the more remarkable in that the species is clearly only binuclear in CHCIBsolution. The bi- to tetranuclear rearrangement,which involves the formal breaking of at least one metal-bromide bond, appears to be fully reversible on redissolution. Furthermore, this feature would appear to be quite general for complexes 1-12; in fact complex 2 was examined crystallographically and shown to be isomorphous with complex 9 and must therefore be tetranuclear, showing that the rearrangement
does not necessarily involve a change in color.
Experimental Section The C, H analyses were carried out with a Perkin-Elmer 240-B microanalyzer. IR spectra were recorded on a Perkin-Elmer 599 spectrophotometer (Nujol mulls between polyethylene plates were used). Molecular weights were determined in CHCl3solution with a Knauer digital osmometer. Molar conductivities were determined in 5 X lo4 M acetone solutions. Decomposition points of the complexes were determined with a Biichi (mod. Dr.Tottoli) apparatus; chlorine and bromine analyses were made as described by White:’ a few milligrams of sucrose being added to facilitate c o m b ~ s t i o n . ~19F ~ NMR spectra were recorded at room temperature on a Varian XL 200 instrument. c ~ s - [ P ~ ( C B X ~ ) ~ ( O C(X ~H =~F, ) ~C1) ] was prepared as described elsewhere% and [MX’,(COD)] (M’ = Pd, Pt; X’ = C1, Br, I) were prepared according to ref 39. (37) White, D. C. Microchim. Acta 1961, 449. (38) Bock, R. Aufschlussmethoden der anorganischen und organischen Chemie; Verlag Chemie: Weinheim, 1972; p 110.
Organometallics 1988, 7, 1323-1328 (a) c ~ ~ - [ P ~ ( C ~ X ~ ) ~(X ( O=CF,~C1). H ~X ) ~=]F. AgC104 (0.256 g, 1.24 mmol) was added to a freshly distilled tetrahydrofuran solution (20 mL) of 0.944 g (0.62 mmol) of
(NBU~)~[P~(~-B~)(C~F~),]~ under nitrogen, and the mixture was stirred at room temperature for 20 min. The resulting suspension was evaporated to dryness, and the residue was extracted from the insoluble residue (AgCl + NBu4C104)with 50 mL of diethyl ether. The solution was evaporated to ca. 5 mL, and, by addition of 20 mL of n-hexane, a white solid was obtained (0.37 g, 90% yield). X = C1 was obtained similarly: 0.45 g (0.257 mmol) of (NBU~),[P~(~-B~)(C~C~~)~]~~ and 0.106 g (0.51 mmol) of AgClO, [0.3 g (80%) yield]. (b) [(C,X,),M(~-X')ZM'(COD)]~ (1-12) (SeeTables I-IV). Complexes 1-12 were obtained by reacting c~s-[M(C&~),(THF),] with [M'X',(COD)] (molar ratio 1:l) in CH2Cl2 A typical preparation is given below. [(C6P5),Pt(p-Br),Pd(COD)],, (2). To a dichloromethane (0.17 g, 0.25 mmol) was solution (20 mL) of c~-[P~(C$~),(THF),] of [PdBr,(COD)], and the solution was added 0.111 g (0.25 "01) stirred for 10 min at room temperature. After evaporation to dryness the resulting residue was washed with n-hexane and stirred for 10 min with 10 mL of benzene. The yellow solid so obtained contains benzene of crystallization. This can be removed (39) Drew, D.; Doyle, J. R. Inorg. Synth. 1972, 13, 47. (40) Walker, N.;Stuart, D. Acta Crystllogr., Sect. A: Found. Crystallogr. 1983, A39, 158. (41) Gould, R. 0.; Taylor, P., University of Edinbugh, 1986.
1323
by heating (80"C for 5 h), affording 0.15 g (61%)of pure complex 2. Crystals suitable for X-ray diffraction were obtained by solvent diffusion (CHzC12/n-hexane)at -30 OC. Table IV collects pertinent information on the preparation of the other complexes.
Acknowledgment. We thank the CAICYT (Spain) for financial support and the Scientific Office of NATO for a travel grant. Registry No. 1 (n = l),113778-23-7; 1 (n = 2), 113778-12-4; 2 (n = l), 113778-24-8; 2 (n = 2), 113778-13-5; 3 (n = l),
113778-33-9;3 (n = 2), 113778-14-6;4 (n = l),113778-25-9; 4 (TI = 2), 113778-15-7;5 (n = l),113778-26-0;5 (n = 2), 113778-16-8; 6 (n = l), 113778-27-1; 6 (n = 2), 113778-17-9; 7 (n l), 113778-28-2;7 (TI. = 2), 113778-18-0;8 (n = l),113778-29-3;8 (n = 2), 113778-19-1;9 (n = l),113778-30-6;9 (n = 2), 113778-20-4; 10 (n = l), 113778-31-7; 10 (n = 2), 113778-21-5; 11 (n = l), 113778-32-8; 11 (n = 2), 113778-22-6;12 (TI = l),113792-86-2;12 (n = 2), 113792-85-1; c~~-[P~(C~F~)Z(OC~HS)~], 97877-50-4; cis[P~(CGC~~)~(OC 97877-51-5; ~ H S ) Z ~ ,(NBU~)Z[P~(~L-B~)(C~F~)ZIZ, 74436-10-5; (NB~),[PdGL-Br)(C6Cld2],, 86392-02-1;[PdCl,(COD)], 12107-56-1;[PdBr2(COD)],12145-47-0;[PtCl,(COD)], 12080-32-9; [PtBr,(COD)], 12145-48-1; [PtI,(COD)], 12266-72-7; cis-[Pt(CJ?5)2(0C,H&,],97877-52-6;Ck-[Pt(C,Cl5),(OC,H~,],97877-53-7.
Supplementary Material Available: Tables of H-atom coordinates and anisotropic thermal parameten (2 pages); a listing of structure factor amplitudes (17 pages). Ordering information
is given on any current masthead page.
X-ray Structural Studies of Tricarbonyl(cyclohexadienyl)manganese, Dicarbonylnitrosyl(cyclohexadienyl)manganese, and Dicarbonylnitrosyl(cyc1ohexadiene)manganese Complexes Steven D. Ittel and John F. Whitney Central Research and Development Department, E. I. du Pont de Nemours and Company, Wilmington, Deia ware 19898
Y.
K. Chung, P. G. Williard, and D. A. Sweigart"
Department of Chemistry, Brown University, Providence, Rhode Island 029 12 Received July 27, 1987
X-ray structures are reported for three complexes relevant to the chemistry of arene functionalization (4) crystallizes in the as mediated by the Mn(C0I3 and Mn(CO),NO fragments. (C6H P~)MII(CO)~ monoclinic space group E 1 / c with a = 10.159 (3) A, b = 9.711 (3) c = 12.990 (3) A, /3 = 94.73 (2)O, 2 = 4, R = 0.029, and R, = 0.030. The phenyl group is positioned exo to the metal, and the dihedal angle between the planar dienyl carbons (C5-C6-C7-C8-C9) and the nonbonded plane (C5-C4-C9) is 36.5O. [(C6H6Me)Mn(CO)zNO]PF6(5) crystallizes in the monoclinic space group P2,ln with a = 13.241 (2) A, b = 9.292 (2) A, c = 11.088 (2) A, @ = 104.87 (1)O, 2 = 4, R = 0.032, and R, = 0.041. The methyl group is exo, and the dihedral angle between the bonded plane (C3-C4-C5-C6-C7) and the nonbonded plane (c3-c2-c7) of the cyclohexadienyl ring is 39.6'. 6H6PhP B U ~ ) M ~ ( C O ) ~ N O(6) ] Pcrystallizes F~ in the monoclinc space group R 1 / c with a = 9.911 (2) , b = 14.624 (3) A, c = 21.771 (4) A, @ = 100.41 (2)O, 2 = 4, R = 0.049, and R, = 0.047. The PBu3 group is exo, and the dihedral angle between the diene plane (CS-CW7-C8) and the nonbonded plane (C5-C4-C3-C8) is 40.8'. The NO ligand in 5 and 6 is positioned under the unsaturated part of the coordinated ring.
1,
LCC
Introduction
It recently has been demonstrated that manganesemediated functionalization of arenes is a promising synthetic procedure.' Thus, the addition of phosphorus,
hydride, and carbon donor nucleophiles to (arene)Mn(CO),+occurs with high regio- and stereoselectivity as shown in Scheme I. The functionalized arene can be (1) Chung, Y. K.; Williard, P. G.; Sweigart, D. A. Organometallics
Contribution no. 4526.
1982, 1, 1053.
0276-7333/88/2307-1323$01.50/0
1988 American Chemical Society
